[0001] This application claims priority to Chinese Patent Application No.
201710687777.3, filed with the Chinese Patent Office on August 11, 2017, and entitled "RANDOM ACCESS
METHOD, DEVICE, AND SYSTEM", which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] Embodiments of this application relate to the communications technologies, and in
particular, to a random access method, a device, and a system.
BACKGROUND
[0003] In real-word application, a terminal device needs to obtain uplink time synchronization
before transmitting uplink data. The uplink time synchronization is obtained by establishing
a communications connection by the terminal device and a network device by using a
random access procedure (Random Access Procedure, RAP).
[0004] An existing random access procedure includes the following steps: sending, by the
terminal device, a random access preamble (Msg 1) to the network device; receiving,
by the terminal device, a random access response (Msg 2) sent by the network device;
sending, by the terminal device, a message 3 (Msg 3) to the network device; and receiving,
by the terminal device, a message 4 (Msg 4), that is, a contention resolution (contention
resolution) message, sent by the network device. For example, the network device may
indicate a terminal device succeeding in the contention resolution by using a physical
downlink control channel (Physical Downlink control channel, PDCCH) scrambled by using
a cell radio network temporary identifier (Cell radio network temporary identifier,
C-RNTI) on an SPCell (a primary cell in a CA scenario, a primary cell of a primary
cell group in a DC scenario, and primary and secondary cells of a secondary cell group
in the DC scenario).
[0005] However, the prior art is only dedicated for a scenario with one transmission and
receiving point (Transmission and receiving point, TRP). For a multi-TRP scenario
introduced in the new radio (New Radio, NR) technology, the prior art does not provide
effective solutions of the contention resolution in the random access procedure.
SUMMARY
[0006] Embodiments of this application provide a random access method, a device, and a system,
so that success of contention resolution of random access or success of random access
by a terminal device can be implemented for a multi-TRP scenario.
[0007] According to a first aspect, an embodiment of this application provides a random
access method, including: determining, by a terminal device, a receiving parameter
of first data; receiving, by the terminal device, a contention resolution message
by using the receiving parameter; and determining, by the terminal device, success
of contention resolution of random access or success of random access based on the
contention resolution message. The first data is at least one of the following data:
an SS-block, a PBCH, a CSI-RS, downlink control information of a random access response,
a random access response, and the like.
[0008] Optionally, before the receiving, by the terminal device, a contention resolution
message by using the receiving parameter, the random access method further includes:
receiving, by the terminal device, configuration information sent by a network device.
The configuration information includes at least one piece of random access configuration,
and a correlation between the first data and the random access configuration. The
random access configuration may include a random access time-frequency resource and/or
a preamble index.
[0009] Optionally, before the receiving, by the terminal device, a contention resolution
message by using the receiving parameter, the random access method further includes:
sending, by the terminal device, a preamble to the network device based on the random
access configuration on the random access time-frequency resource. There is a correspondence
between the preamble and the preamble index. Herein, the random access configuration
includes at least one of the random access time-frequency resource and the preamble
index corresponding to the sent preamble.
[0010] Optionally, before the receiving, by the terminal device, a contention resolution
message by using the receiving parameter, the random access method further includes:
receiving, by the terminal device, a random access response sent by the network device.
A receiving parameter of the random access response is the same as the receiving parameter
of the first data, and/or a receiving parameter of the downlink control information
of the random access response is the same as the receiving parameter of the first
data.
[0011] According to a second aspect, an embodiment of this application provides a random
access method, including: receiving, by a network device, a preamble sent by a terminal
device on a random access time-frequency resource; determining, by the network device,
a sending parameter of first data based on the random access time-frequency resource
and/or the preamble; and sending, by the network device, a contention resolution message
to the terminal device by using the sending parameter, where the contention resolution
message is used to instruct the terminal device to determine success of contention
resolution of random access or success of random access. The first data is at least
one of the following data: an SS-block, a PBCH, a CSI-RS, downlink control information
of a random access response, and a random access response.
[0012] Optionally, the determining, by the network device, a sending parameter of first
data based on the random access time-frequency resource and/or the preamble includes:
determining, by the network device, random access configuration based on the preamble
and/or the random access time-frequency resource, where there is a correspondence
between the preamble and a preamble index; and determining, by the network device,
the sending parameter of the first data based on the random access configuration and
a correlation between the first data and the random access configuration.
[0013] Optionally, before the sending, by the network device, a contention resolution message
to the terminal device by using the sending parameter, the random access method further
includes: sending, by the network device, configuration information to the terminal
device. The configuration information includes at least one piece of random access
configuration, and a correlation between the first data and the random access configuration.
The random access configuration may include the random access time-frequency resource
and/or the preamble index.
[0014] Optionally, before the sending, by the network device, a contention resolution message
to the terminal device by using the sending parameter, the random access method further
includes: sending, by the network device, the random access response to the terminal
device. A sending parameter of the random access response is the same as the sending
parameter of the first data, and/or a sending parameter of the downlink control information
of the random access response is the same as the sending parameter of the first data.
[0015] According to a third aspect, an embodiment of this application provides a random
access device, including a determining module and a receiving module. The determining
module is configured to determine a receiving parameter of first data; the receiving
module is configured to receive a contention resolution message by using the receiving
parameter; and the determining module is further configured to determine success of
contention resolution of random access or success of random access based on the contention
resolution message. The first data is at least one of the following data: an SS-block,
a PBCH, a CSI-RS, downlink control information of a random access response, a random
access response, and the like.
[0016] Optionally, the receiving module is further configured to: before receiving the contention
resolution message by using the receiving parameter, receive configuration information
sent by a network device. The configuration information includes at least one piece
of random access configuration, and a correlation between the first data and the random
access configuration. The random access configuration may include a random access
time-frequency resource and/or a preamble index.
[0017] Optionally, the random access device further includes: a sending module, configured
to: before the receiving module receives the contention resolution message by using
the receiving parameter, send a preamble to the network device based on the foregoing
random access configuration on the random access time-frequency resource. There is
a correspondence between the preamble and the preamble index.
[0018] Optionally, the receiving module is further configured to: before receiving the contention
resolution message by using the receiving parameter, receive a random access response
sent by the network device. A receiving parameter of the random access response is
the same as the receiving parameter of the first data, and/or a receiving parameter
of the downlink control information of the random access response is the same as the
receiving parameter of the first data.
[0019] According to a fourth aspect, an embodiment of this application provides a random
access device, including: a receiving module, configured to receive a preamble sent
by a terminal device on a random access time-frequency resource; a determining module,
configured to determine a sending parameter of first data based on the random access
time-frequency resource and/or the preamble; and a sending module, configured to send
a contention resolution message to the terminal device by using the sending parameter,
where the contention resolution message is used to instruct the terminal device to
determine success of contention resolution of random access or success of random access.
The first data is at least one of the following data: an SS-block, a PBCH, a CSI-RS,
downlink control information of a random access response, a random access response,
and the like.
[0020] Optionally, the determining module may be specifically configured to: determine random
access configuration based on the preamble and/or the random access time-frequency
resource, where there is a correspondence between the preamble and a preamble index;
and determine the sending parameter of the first data based on the random access configuration
and a correlation between the first data and the random access configuration.
[0021] Optionally, the sending module is further configured to: before sending the contention
resolution message to the terminal device by using the sending parameter, send configuration
information to the terminal device. The configuration information includes at least
one piece of random access configuration and a correlation between the first data
and the random access configuration. The random access configuration may include the
random access time-frequency resource and/or the preamble index.
[0022] Optionally, the sending module is further configured to: before sending the contention
resolution message to the terminal device by using the sending parameter, send a random
access response to the terminal device. A sending parameter of the random access response
is the same as the sending parameter of the first data, and/or a sending parameter
of the downlink control information of the random access response is the same as the
sending parameter of the first data.
[0023] According to a fifth aspect, an embodiment of this application provides a terminal
device, including: a processor, configured to determine a receiving parameter of first
data and send an indication to a transceiver; a transceiver, configured to receive
a contention resolution message based on the indication of the processor by using
the receiving parameter; and the processor, further configured to determine success
of contention resolution of random access or success of random access based on the
contention resolution message. The first data is at least one of the following data:
an SS-block, a PBCH, a CSI-RS, downlink control information of a random access response,
a random access response, and the like.
[0024] Optionally, the transceiver is further configured to: before receiving the contention
resolution message by using the receiving parameter, receive configuration information
sent by a network device, where the configuration information includes at least one
piece of random access configuration and a correlation between the first data and
the random access configuration, and the random access configuration includes a random
access time-frequency resource and/or a preamble index.
[0025] Optionally, the transceiver is further configured to: before receiving the contention
resolution message by using the receiving parameter, send a preamble to the network
device based on the random access configuration on the random access time-frequency
resource, where there is a correspondence between the preamble and the preamble index.
[0026] Optionally, the transceiver is further configured to: before receiving the contention
resolution message by using the receiving parameter, receive the random access response
sent by the network device, where a receiving parameter of the random access response
is the same as the receiving parameter of the first data, and/or a receiving parameter
of the downlink control information of the random access response is the same as the
receiving parameter of the first data.
[0027] According to a sixth aspect, an embodiment of this application provides a network
device, including: a transceiver, configured to receive a preamble sent by a terminal
device on a random access time-frequency resource; a processor, configured to determine
a sending parameter of first data based on the random access time-frequency resource
and/or the preamble and send an indication to the transceiver; and the transceiver,
further configured to send a contention resolution message to the terminal device
by using the sending parameter based on the indication of the processor, where the
contention resolution message is used to instruct the terminal device to determine
success of contention resolution of random access or success of random access. The
first data is at least one of the following data: an SS-block, a PBCH, a CSI-RS, downlink
control information of a random access response, a random access response, and the
like.
[0028] Optionally, the processor is specifically configured to: determine random access
configuration based on the preamble and/or the random access time-frequency resource,
where there is a correspondence between the preamble and a preamble index; and determine
the sending parameter of the first data based on the random access configuration and
a correlation between the first data and the random access configuration.
[0029] Optionally, the transceiver is further configured to: before sending the contention
resolution message to the terminal device by using the sending parameter, send configuration
information to the terminal device, where the configuration information includes at
least one piece of random access configuration and a correlation between the first
data and the random access configuration, and the random access configuration includes
the random access time-frequency resource and/or the preamble index.
[0030] Optionally, the transceiver is further configured to: before sending the contention
resolution message to the terminal device by using the sending parameter, send the
random access response to the terminal device, where a sending parameter of the random
access response is the same as the sending parameter of the first data, and/or a sending
parameter of the downlink control information of the random access response is the
same as the sending parameter of the first data.
[0031] Based on any implementation of the first aspect to the sixth aspect of this application:
Optionally, the random access configuration further includes at least one of the following:
a root sequence index, used to generate a preamble sequence;
a high speed flag, used to generate a selection preamble;
a preamble set or a quantity of preambles;
a preamble power ramp parameter;
an initial receiving target power of a preamble;
a maximum quantity of transmission times of the preamble;
a window length of a random access response; and
a contention resolution timer of a MAC.
Optionally, the receiving parameter includes at least one of the following parameters:
an angle of arrival, a dominant angle of arrival, an average angle of arrival, power
angular spectrum of the angle of arrival, an angle of direction, power angular spectrum
of an angle of departure, a transmit/receive channel correlation, transmit/receive
beamforming, a spatial channel correlation, and the like.
[0032] Optionally, the sending parameter includes at least one of the following parameters:
an angle of departure, an angle of direction, power angular spectrum of the angle
of departure, a transmit/receive channel correlation, transmit/receive beamforming,
a spatial channel correlation, and the like.
[0033] Optionally, the contention resolution message is a downlink control channel carrying
an identifier of a terminal device.
[0034] According to a seventh aspect, an embodiment of this application provides a terminal
device, including: a processor, a memory, and a computer program that is stored on
the memory and that can be executed by the processor. The processor executes the computer
program to implement the method according to the first aspect.
[0035] According to an eighth aspect, an embodiment of this application provides a network
device, including: a processor, a memory, and a computer program that is stored on
the memory and that can be executed by the processor. The processor executes the computer
program to implement the method according to the second aspect.
[0036] According to a ninth aspect, an embodiment of this application provides a terminal
device, including at least one processing element (or chip) configured to perform
the method according to the first aspect.
[0037] According to a tenth aspect, an embodiment of this application provides a network
device, including at least one processing element (or chip) configured to perform
the method according to the second aspect.
[0038] According to an eleventh aspect, an embodiment of this application provides a program.
The program is configured to perform the method according to the first aspect when
executed by a processor of a terminal device.
[0039] According to a twelfth aspect, an embodiment of this application provides a program.
The program is configured to perform the method according to the second aspect when
executed by a processor of a network device.
[0040] According to a thirteenth aspect, an embodiment of this application provides a computer
program product, including the program according to the eleventh aspect.
[0041] According to a fourteenth aspect, an embodiment of this application provides a computer
program product, including the program according to the twelfth aspect.
[0042] According to a fifteenth aspect, an embodiment of this application provides a computer
readable storage medium. When an instruction in the computer readable storage medium
is executed by a processor of a terminal device, the terminal device is enabled to
perform the method according to the first aspect.
[0043] According to a sixteenth aspect, an embodiment of this application provides a computer
readable storage medium. When an instruction in the computer readable storage medium
is executed by a processor of a network device, the network device is enabled to perform
the method according to the second aspect.
[0044] According to a seventeenth aspect, an embodiment of this application provides a communications
system, including the terminal device according to the fifth aspect and the network
device according to the sixth aspect.
[0045] The embodiments of this application provide the random access method, the device,
and the system. The terminal device receives the contention resolution message by
using the receiving parameter of the first data, and determines the success of contention
resolution of random access or the success of random access based on the contention
resolution message. The first data is at least one of the following data: an SS-block,
a CSI-RS, downlink control information of a random access response, and a random access
response, so that for a multi-TRP scenario, the terminal device can pertinently distinguish
whether the received contention resolution message is a contention resolution message
corresponding to current random access. On the one hand, the terminal device does
not continue performing random access after receiving the contention resolution message
corresponding to the current random access, that is, in the random access procedure,
a random access preamble is not sent to the network device any more; on the other
hand, the terminal device is enabled to continue performing random access before the
contention resolution message corresponding to the current random access is not received,
for example, waiting the contention resolution message corresponding to the current
random access or resending the random access preamble to the network device, to implement
success of the contention resolution of the random access or success of the random
access by the terminal device for the multi-TRP scenario.
BRIEF DESCRIPTION OF DRAWINGS
[0046]
FIG. 1 is a schematic diagram of a communications system according to an embodiment
of this application;
FIG. 2 is a flowchart of a random access method according to an embodiment of this
application;
FIG. 3 is a signaling interworking diagram of a random access method according to
another embodiment of this application;
FIG. 4 is an application example of a random access method according to an embodiment
of this application;
FIG. 5 is a signaling interworking diagram of a random access method according to
another embodiment of this application;
FIG. 6 is an application example of a random access method according to another embodiment
of this application;
FIG. 7 is a schematic structural diagram of a random access device according to an
embodiment of this application;
FIG. 8 is a schematic structural diagram of a random access device according to another
embodiment of this application;
FIG. 9 is a schematic structural diagram of a terminal device according to an embodiment
of this application; and
FIG. 10 is a schematic structural diagram of a network device according to an embodiment
of this application.
DESCRIPTION OF EMBODIMENTS
[0047] FIG. 1 is a schematic diagram of a communications system according to an embodiment
of this application. As shown in FIG. 1, the communications system includes a network
device and at least one terminal device. The terminal device is located in a coverage
of the network device and communicates with the network device, to implement the technical
solutions provided in each embodiment of this application. The communications system
in this embodiment may be applicable to a multi-TRP scenario.
[0048] In the embodiments of this application, each embodiment is described with reference
to the network device and the terminal device. The network device and the terminal
device may work on a licensed frequency band or a license-exempt frequency band.
[0049] The terminal device may also be referred to as user equipment (User Equipment, UE),
an access terminal, a subscriber unit, a subscriber station, a mobile station, a mobile
console, a remote station, a remote terminal, a mobile device, a user terminal, a
terminal, a wireless communications device, a user agent, or a user apparatus. The
terminal device may be a station (STATION, ST) in a wireless local area network (Wireless
Local Area Networks, WLAN), or may be a cellular phone, a cordless telephone set,
a session initiation protocol (Session Initiation Protocol, SIP) phone, a wireless
local loop (Wireless Local Loop, WLL) station, a personal digital assistant (Personal
Digital Assistant, PDA) device, a handheld device having a wireless communications
function, a computing device, or another processing device connected to a wireless
modem, an in-vehicle device, a wearable device, a terminal device in a next generation
communications system, such as the fifth-generation (the fifth-generation, 5G) network
or a terminal device in a future evolved public land mobile network (Public Land Mobile
Network, PLMN), a terminal device in an NR system, or the like.
[0050] As an example but not a limitation, in this embodiment of this application, the terminal
device may further be a wearable device. The wearable device may also be referred
to as a wearable intelligent device, a general term for wearable devices, such as
glasses, a glove, a watch, a cloth, and shoes, developed by performing intelligent
designs for daily wear by using wearable technologies. The wearable device is a portable
device that is worn directly on a body or integrated into a cloth or an accessory
of a user. The wearable device is not only a hardware device, but moreover implements
a powerful function through software support, data exchange, and cloud interaction.
A generalized wearable intelligent device includes a device with a full function and
large size, and can implement all or some functions without depending on a smartphone,
such as a smart watch or smart glasses, and a device, such as various smart bracelets
or smart jewelry for monitoring vital signs, that focuses on only one type of application
function and needs to work with another device such as a smartphone.
[0051] In addition, the network device is also referred to as a radio access network (Radio
Access Network, RAN) device and is a device for accessing the terminal device into
a wireless network. The network device may be an evolved NodeB (Evolutional Node B,
eNB or eNodeB), a relay station, an access point in a long term evolution (Long Term
Evolution, LTE), a network device in a 5G network, a network device in a future evolved
PLMN network, a new radio NodeB (new radio Node B, gNodeB) in an NR system, or the
like. This is not limited herein.
[0052] In addition, in this embodiment of this application, the network device provides
a service for a cell, and the terminal device communicates with the network device
by using a transmission resource (for example, a frequency domain resource, or a spectrum
resource) used by the cell. The cell may be a cell corresponding to the network device
(for example, a base station), and the cell may belong to a macro base station, or
may belong to a base station corresponding to a small cell (small cell). The small
cell herein may include a metro cell (Metro cell), a micro cell (Micro cell), a pico
cell (Pico cell), a femto cell (Femto cell), and the like. The small cells have features
of small coverage and low transmit power, and are applicable to a service providing
a high-rate data transmission.
[0053] A random access procedure is usually triggered by one of the following seven events:
- 1) Establishment of a wireless connection when initially accessed, that is, the terminal
device switches from a radio resource control idle (Radio Resource Control Idle, RRC_IDLE)
state to an RRC connected (RRC Connected, RRC CONNECTED) state;
- 2) RRC connection re-establishment procedure (RRC Connection Re-establishment procedure),
used to re-establish the RRC connection;
- 3) Handover (handover), switch from one cell to another cell;
- 4) In the RRC CONNECTED state, uplink time is in a "non-synchronization" state when
downlink data arrives (for example, in this case, a hybrid automatic repeat request
HARQ ACK/NACK needs to be replied);
- 5) In the RRC CONNECTED state, uplink time is in a "non-synchronization" state or
there is no available physical uplink control channel (Physical Uplink Shared Channel,
PUCCH) resource for scheduling request (Scheduling Request, SR) transmission when
uplink data arrives (for example, a measurement report needs to be reported or user
data needs to be sent);
- 6) In the RRC_CONNECTED state, timing advance (timing advance) is needed for positioning
the terminal device; and
- 7) State switching from an RRC_INACTIVE state to the RRC_CONNECTED state.
[0054] A terminal device in the RRC_CONNECTED state is a terminal device maintaining an
RRC connection between the terminal device and an access network device and a connection
between the access network device and a core network device. A terminal device in
the RRC_INACTIVE state is a terminal device maintaining the connection between the
access network device and the core network device, without the RRC connection between
the terminal device and the access network device. A terminal device in the RRC_IDLE
state is a terminal device without the connection between the access network device
and the core network device and without the RRC connection between the terminal device
and the access network device.
[0055] The random access procedure includes:
- (1) A contention based (Contention based) random access procedure: applicable to the
first five types of the foregoing six types of events; and
- (2) A non-contention based (Non-contention based or Contention-Free based) random
access procedure: applicable to three types: 3), 4), 6), and 7) of the foregoing seven
types of events.
[0056] A beam (beam) may be understood as a space resource, and may refer to a sending or
receiving precoding vector with directionality of energy transmission. In addition,
the sending or receiving precoding vector can be identified by using index information.
The directionality of energy transmission may refer to performing precoding processing
on a to-be-sent signal by using the precoding vector. A signal after the precoding
processing has particular space directionality, and a signal after the precoding processing
by using the precoding vector has relatively good receive power, for example, a receiving
demodulation signal-to-noise ratio is satisfied. The directionality of energy transmission
may also refer to that same signals that are received by using the precoding vector
and that are sent from different special locations have different receive power. Optionally,
a same communications device, such as a terminal device or a network device, may have
different precoding vectors, and different communications devices may also have different
precoding vectors, that is, correspond to different beams.
[0057] For configuration or capabilities of a communications device, one communications
device may use one or more of different precoding vectors at a same moment, that is,
one or more beams may be formed at the same time. Beam information may be identified
by using the index information. Optionally, the index information may correspond to
a resource identity (identity, ID) for configuring the terminal device. For example,
the index information may correspond to an ID, an index (index), or a resource of
a configured channel state information-reference signal (Channel status information
Reference Signal, CSI-RS), or may correspond to an ID or a resource of a configured
uplink sounding reference signal (Sounding Reference Signal, SRS). Alternatively,
optionally, the index information may also be index information explicitly or implicitly
carried by a signal or a channel, where the signal or the channel is carried by a
beam. For example, the index information includes but is not limited to index information
that is of a beam indicated by a synchronous signal or a broadcast channel and that
is sent by using the beam. The resource may be at least one of the following: a time
domain, a frequency domain, and a code domain (sequence).
[0058] It should be understood that the term "and/or" in this specification describes only
an association relationship for describing associated objects and represents that
three relationships may exist. For example, A and/or B may represent the following
three cases: Only A exists, both A and B exist, and only B exists.
[0059] FIG. 2 is a flowchart of a random access method according to an embodiment of this
application. As shown in FIG. 2, the method in this embodiment includes the following
steps.
[0060] S201. A terminal device determines a receiving parameter of first data.
[0061] The first data may be at least one of the following data: a synchronization signal
block (Synchronization Signal block, SS-block), a physical broadcast channel (Physical
Broadcast Channel, PBCH), a CSI-RS, downlink control information of a random access
response, a random access response, and the like. The CSI-RS is used for channel estimation,
beam management, or cell mobility measurement; and the SS-block may include at least
one of a primary synchronization signal (Primary Synchronization Signal, PSS), a secondary
synchronization signal (Secondary Synchronization Signal, SSS), and the like. Optionally,
the SS-block or the CSI-RS may be transmitted by using a beam. The receiving parameter
may be an antenna parameter, a receiving parameter of the beam, a spatial receive
parameter (spatial receive parameters), or the like.
[0062] Specifically, the first data may be data received in the random access procedure,
or may be data received before the random access procedure is triggered. This is not
limited in this embodiment of this application. In addition, the receiving parameter
of the first data is a parameter used when the terminal device receives the first
data.
[0063] It should also be noted that, the first data is associated with random access configuration
determined by the terminal device. For example, when the first data is the SS-block,
receiving parameters corresponding to different SS-blocks may be different, and the
terminal device does not need to determine the receiving parameters of all the SS-blocks
and only needs to determine a receiving parameter of an SS-block associated with a
random access time-frequency resource and/or a preamble index used to initiate the
random access. For another example, when the first data is the CSI-RS, receiving parameters
corresponding to different CSI-RSs may be different, and the terminal device does
not need to determine the receiving parameters of all the CSI-RSs and only needs to
determine a receiving parameter of a CSI-RS associated with a random access time-frequency
resource and/or a preamble index used to initiate the random access. Alternatively,
when the first data is the PBCH, receiving parameters corresponding to different PBCHs
may be different, and the terminal device does not need to determine the receiving
parameters of all the PBCHs and only needs to determine a receiving parameter of a
PBCH associated with a random access time-frequency resource and/or a preamble index
used to initiate the random access. In addition, the terminal device may distinguish
the different SS-blocks based on identifiers of the SS-blocks. Similarly, the terminal
device may distinguish the different CSI-RSs based on configured identifiers of the
CSI-RSs.
[0064] The terminal device determines the receiving parameter of the first data before the
random access procedure is triggered or in the random access procedure. Optionally,
the terminal device stores the receiving parameter of the first data. Optionally,
the receiving parameter may include at least one of the following parameters: an angle
of arrival (angle of arrival, AoA), a dominant AoA (Dominant AoA), an average AoA
(average AoA), power angular spectrum (Power Angular Spectrum, PAS) of the angle of
arrival, an angle of direction (angle of Direction, AOD), power angular spectrum of
an angle of departure, a transmit/receive channel correlation (transmit/receive channel
correlation), transmit/receive beamforming (transmit/receive beamforming), a spatial
channel correlation, and the like.
[0065] S202. The terminal device receives a contention resolution message by using the receiving
parameter.
[0066] In the random access procedure, the terminal device receives the contention resolution
message from a network device by using the foregoing determined receiving parameter
of the first data. The contention resolution message is sent by the network device
to the terminal device.
[0067] In specific implementation, the contention resolution message may be a downlink control
channel carrying an identifier of the terminal device. Alternatively, the contention
resolution message carries some or all information of a message 3 sent by the terminal
device, to specify a terminal device succeeding in contention of the random access.
For example, the contention resolution message is a downlink control channel at a
bit at which a cyclic redundancy check (Cyclic Redundancy Check, CRC) is scrambled
by using the identifier of the terminal device. The downlink control channel is used
to transmit downlink assignment (downlink assignment) and/or uplink grant (uplink
grant). For example, the downlink control channel may be a PDCCH. The downlink assignment
is used to indicate a transmission resource of downlink data, and the uplink grant
is used to assign a transmission resource of uplink data. If the contention resolution
message is the downlink assignment, the terminal device receives the downlink data
based on the downlink assignment, and sends a feedback of the downlink data to the
network device, where the feedback is used to inform the network device whether the
downlink data is successfully decoded by the terminal device; and if the contention
resolution message is the uplink grant, the terminal device sends the uplink data
to the network device based on the uplink grant. If the contention resolution message
is some or all information of the message 3 sent by the terminal device, the terminal
device sends a feedback of the contention resolution message to the network device,
where the feedback is used to inform the network device that the contention resolution
message is successfully decoded by the terminal device; and if the decoding is not
successful, the terminal device does not need to send the feedback to the network
device.
[0068] The identifier of the terminal device is an identifier of the terminal device in
a cell. Optionally, the identifier of the terminal device is a cell radio network
temporary identifier (cell radio network temporary identifier, C-RNTI).
[0069] S203. The terminal device determines success of contention resolution of random access
or success of random access based on the contention resolution message.
[0070] For example, if the terminal device determines that the contention resolution message
carries the identifier of the terminal device, it is considered that contention resolution
of random access is successful or it is determined that random access is successful;
or if the terminal device determines that the contention resolution message carries
some or all information of the message 3 sent by the terminal device, it is considered
that contention resolution of random access is successful or it is determined that
random access is successful.
[0071] In this embodiment, the terminal device receives the contention resolution message
by using the receiving parameter of the first data, and determines success of contention
resolution of random access or success of random access based on the contention resolution
message. The first data is at least one of the following data: an SS-block, a CSI-RS,
downlink control information of a random access response, and a random access response,
so that for a multi-TRP scenario, the terminal device can pertinently distinguish
whether the received contention resolution message is a contention resolution message
corresponding to current random access. On the one hand, the terminal device does
not continue performing random access after receiving the contention resolution message
corresponding to the current random access, that is, in the random access procedure,
a random access preamble is not sent to the network device any more; on the other
hand, the terminal device is enabled to continue performing random access before the
contention resolution message corresponding to the current random access is not received,
for example, waiting the contention resolution message corresponding the current random
access or resending the random access preamble to the network device, to implement
success of the contention resolution of the random access or success of the random
access by the terminal device for the multi-TRP scenario.
[0072] The following descriptions are made with reference to interaction between the network
device and the terminal device.
[0073] FIG. 3 is a signaling interworking diagram of a random access method according to
another embodiment of this application. As shown in FIG. 3, the random access method
includes the following steps.
[0074] S301. A terminal device receives configuration information sent by a network device.
[0075] The configuration information includes at least one piece of random access configuration,
and a correlation between first data and the random access configuration. The random
access configuration may include a random access time-frequency resource and/or a
preamble index. In addition, there may be one or more random access time-frequency
resources and/or preamble indexes. This is not limited in this application. The step
is optional. S301 is performed only in first-time random access or in new random access
after the configuration information is updated.
[0076] For example, the configuration information includes random access configuration 1,
random access configuration 2, a correlation 1 between the random access configuration
1 and an SS-block 1, and a correlation 2 between the random access configuration 2
and an SS-block 2. In this case, if the terminal device determines to perform random
access based on the random access configuration 1, the terminal device determines
that the SS-block 1 associated with the random access configuration 1 is the first
data described in this specification. In subsequent S305, the terminal device determines
a receiving parameter of the first data, and it may be understood as: the terminal
device determines a receiving parameter of the SS-block 1.
[0077] Optionally, the random access configuration may further include at least one of the
following: a root sequence index (rootSequenceIndex), used to generate a preamble
sequence; a high speed flag (highSpeedFlag), used to generate a selection preamble;
a preamble set or a quantity of preambles; a preamble power ramp parameter; an initial
receiving target power of a preamble; a maximum quantity of transmission times of
the preamble (PreambleTransMax); a window length of a random access response (ra-ResponseWindowSize);
a contention resolution timer of a medium access control (Medium Access Control, MAC),
and the like.
[0078] S302. The terminal device sends a preamble to the network device based on the random
access configuration included in the configuration information on the random access
time-frequency resource.
[0079] There is a correspondence between the preamble (Preamble) and the preamble index.
For a relationship between the preamble and the preamble index, refer to the prior
art, and details are not described herein again. The preamble, for example, is the
preamble sequence.
[0080] For example, if the preamble index available for the terminal device includes a preamble
index 1, a preamble index 2, and a preamble index 3, the preamble index corresponding
to the preamble sent by the terminal device is in a range of the preamble index 1,
the preamble index 2, and the preamble index 3. To be specific, the preamble index
corresponding to the preamble sent by the terminal device is one of the foregoing
three preamble indexes.
[0081] The terminal device needs the following conditions to successfully send the preamble:
- 1) Select a preamble index;
- 2) Select a random access time-frequency resource used to send the preamble;
- 3) Determine a corresponding random access radio network temporary identifier (Random
Access Radio Network Temporary Identifier, RA-RNTI); and
- 4) Determine a target receiving power (PREAMBLE_RECEIVED_TARGET_POWER).
[0082] The foregoing conditions may be predefined, configured by higher layer signaling,
or obtained or determined in another manner. This is not limited in this application.
[0083] With reference to the foregoing descriptions, the random access configuration may
include the random access time-frequency resource and/or the preamble index, and the
step may be understood as follows.
[0084] It may be understood that, when the random access configuration includes the random
access time-frequency resource, the step is specifically that the terminal device
sends the preamble to the network device on any random access time-frequency resource
included in the random access configuration. In this case, the preamble is a public
preamble, that is, the preamble does not need to be associated with the first data
and may be obtained through another configuration.
[0085] When the random access configuration includes the preamble index, the step is specifically
that the terminal device sends the preamble corresponding to any preamble index included
in the random access configuration, to the network device on the random access time-frequency
resource. In this case, the random access time-frequency resource is a public random
access time-frequency resource, that is, the random access time-frequency resource
does not need to be associated with the first data and may be obtained by using other
configuration.
[0086] When the random access configuration includes the random access time-frequency resource
and the preamble index, the step is specifically that the terminal device sends the
preamble corresponding to any preamble index included in the random access configuration
to the network device on any random access time-frequency resource included in the
random access configuration.
[0087] For example, the configuration information includes two pieces of random access configuration:
random access configuration 1 and random access configuration 2, where the random
access configuration 1 is associated with the SS-block 1, and the random access configuration
2 is associated with the SS-block 2. The terminal device selects the SS-block 2 based
on downlink measurement, to perform random access. This is specifically reflected
as: the terminal device uses the random access configuration associated with the SS-block
2 to perform random access. For example, the terminal device sends the preamble to
the network device by using any random access time-frequency resource included in
the random access configuration associated with the SS-block 2.
[0088] Correspondingly, the network device receives the preamble sent by the terminal device
on the random access time-frequency resource.
[0089] S303. The network device determines a sending parameter of the first data based on
the random access time-frequency resource and/or the preamble.
[0090] Optionally, the step specifically includes: determining, by the network device, the
random access configuration based on the preamble sent by the terminal device and/or
the random access time-frequency resource used to send the preamble, where there is
a correspondence between the preamble and the preamble index; and determining, by
the network device, the sending parameter of the first data based on the determined
random access configuration and a correlation between the first data and the random
access configuration.
[0091] Because at least one of the preamble sent by the terminal device and the random access
time-frequency resource used to send the preamble is included or corresponds to the
determined random access configuration, the random access configuration may be determined
based on the preamble sent by the terminal device and the random access time-frequency
resource used to send the preamble. In addition, as described above, the configuration
information includes the random access configuration and the correlation between the
first data and the random access configuration. Therefore, the network device may
determine the first data based on the determined random access configuration and the
correlation between the first data and the random access configuration, and thereby
determine the sending parameter of the first data.
[0092] The sending parameter may include at least one of the following parameters: an angle
of departure, an angle of direction, power angular spectrum of the angle of departure,
a transmit/receive channel correlation, transmit/receive beamforming, a spatial channel
correlation, and the like.
[0093] S304. The network device sends a random access response to the terminal device.
[0094] A sending parameter of the random access response is the same as the sending parameter
of the first data, and/or, a sending parameter of downlink control information of
the random access response is the same as the sending parameter of the first data.
[0095] Correspondingly, the terminal device receives the random access response sent by
the network device.
[0096] A receiving parameter of the random access response is the same as the receiving
parameter of the first data, and/or, a receiving parameter of downlink control information
of the random access response is the same as the receiving parameter of the first
data. For example, the terminal device receives the random access response of the
network device to the preamble by using a receiving parameter of an SS-block or a
CSI-RS.
[0097] Optionally, after sending the preamble, the terminal device monitors a PDCCH within
a time window of the random access response based on a corresponding RA-RNTI, to receive
the random access response to the preamble. If the terminal device does not receive
the random access response replied by the network device within the time window of
the random access response, the terminal device considers that the random access procedure
fails.
[0098] For example, the time window of the random access response starts from a subframe
sending the preamble (if the preamble covers a plurality of subframes on a time domain,
calculate a last subframe) + 3 subframes, and continues a quantity of subframes the
same as a size of the time window of the random access response.
[0099] The random access response includes uplink grant. Optionally, the random access response
further includes an uplink timing advance. The uplink grant includes a physical resource.
Optionally, the uplink grant further includes at least one of the following: a modulation
and coding scheme (Modulation and Code Scheme, MCS), a channel quality information
(channel quality information, CQI) request, and the like.
[0100] Further, the random access response may further be configured to trigger the terminal
device to receive the CSI-RS or measure the CSI-RS.
[0101] S305. The terminal device sends second data to the network device.
[0102] The second data includes a cell identifier of the terminal device. The second data
may specifically be data similar to the message 3, including the message 3. In addition,
because states of the terminal device and application scenarios of the terminal device
are different, the second data may also be different.
[0103] In specific implementation, the terminal device may send the second data to the network
device based on the uplink grant; or the terminal device may send the second data
to the network device based on the uplink grant and the uplink timing advance.
[0104] Optionally, the second data may further include a beam identifier. Specifically,
the terminal device performs beam measurement on the CSI-RS based on the random access
response, determines a beam having a best or better measurement result, and adds a
beam identifier of the beam to the second data. If the terminal device performs random
access by using the random access configuration associated with the SS-block, the
beam identifier may be a time index (time index), and the time index is indicated
by using a PBCH in the SS-block. If the terminal device performs random access by
using the random access configuration associated with the CSI-RS, the beam identifier
may be a configuration identifier of the CSI-RS, for example, an index or the like.
[0105] S306. The terminal device determines the receiving parameter of the first data.
[0106] The step is the same as S201, and details are not described herein again.
[0107] S307. The network device sends a contention resolution message to the terminal device
by using the sending parameter of the first data, where the contention resolution
message is used to instruct the terminal device to determine success of contention
resolution of random access or success of random access.
[0108] Correspondingly, the terminal device receives the contention resolution message by
using the receiving parameter of the first data. In other words, if the terminal receives
a message by using a receiving parameter that is not of the first data, for example,
the message is a PDCCH carrying a C-RNTI, the terminal device cannot determine success
of contention resolution or success of random access based on the message.
[0109] The step is the same as S202, and details are not described herein again.
[0110] S308. The terminal device determines success of contention resolution of random access
or success of random access based on the contention resolution message.
[0111] The step is the same as S203, and details are not described herein again.
[0112] It should be noted that, this application is not limited to the foregoing performing
sequence. A person skilled in the art may understand that step S303 can be performed
after step S302 and before S307, and S306 can be performed before S307. A specific
performing sequence is not limited in this application.
[0113] Optionally, based on the foregoing embodiments, the random access method may further
include: receiving, by the terminal device, indication information sent by the network
device, where the indication information is used to trigger the terminal device to
perform random access. Optionally, the indication information is carried by using
physical layer signaling. The physical layer signaling is, for example, a PDCCH order.
[0114] Optionally, the indication information includes at least one first identifier. The
at least one first identifier is used to instruct the terminal device to determine
the random access time-frequency resource. For example, the first identifier may be
a time index (time index).
[0115] Further, the first identifier is further used to identify the SS-block and/or the
CSI-RS. Specifically, the first identifier is used to identify the CSI-RS, and it
may be understood that the first identifier is used to identify configuration of the
CSI-RS. The configuration of the CSI-RS includes a time-frequency resource of the
CSI-RS. Alternatively, the configuration of the CSI-RS may further include at least
one of the following: a sequence, a port, and the like of the CSI-RS.
[0116] Optionally, the indication information may further include a second identifier. The
second identifier is used to instruct the terminal device to determine the receiving
parameter used to receive the random access response, and the second identifier may
specifically be a configuration identifier of the CSI-RS. The configuration of the
CSI-RS includes the time-frequency resource of the CSI-RS. The receiving parameter
may be a receiving beam, an antenna parameter, and the like that are associated with
the CSI-RS.
[0117] The following describes an application of the random access method provided in the
foregoing embodiments by using FIG. 4 as an example.
[0118] As shown in FIG. 4, a cell under one base station includes two TRPs: a TRP 1 and
a TRP 2. A terminal device and the TRP 2 are performing data transmission. Primary
synchronization signals and/or secondary synchronization signals included in SS-blocks
sent by the TRP 1 and the TRP 2 are same. The terminal device receives indication
information sent by the base station by using the TRP 2. The indication information
is used to trigger the terminal device to perform random access, to obtain uplink
timing advance of a terminal-TRP 1. The indication information, for example, may be
a PDCCH order. Specifically, the terminal device sends a preamble to the TRP 1; the
terminal device receives a random access response from the TRP 1; the terminal device
sends second data to the TRP 1; and if the random access is contention-based, the
terminal device receives a message sent by the base station from the TRP 1, for example,
the message is a PDCCH carrying a C-RNTI. In this case, the message is a contention
resolution message, and the terminal device determines success of contention resolution
of random access or success of random access based on the contention resolution message.
When the terminal device receives a message sent by the base station by using the
TRP 2, for example, the message is a PDCCH carrying a C-RNTI, the terminal device
cannot determine success of contention resolution or success of random access based
on the message.
[0119] The foregoing embodiment is contention-based random access. In non-contention based
random access, because a preamble is dedicated for a particular terminal device, there
is no contention; and because the terminal device has owned a unique identifier, such
as a C-RNTI in an access cell, a network device does not need to allocate an identifier
for the terminal device. Therefore, the non-contention based random access only includes:
sending, by the terminal device, the preamble to the network device; and receiving,
by the terminal device, a random access response sent by the network device.
[0120] It should be noted that: (1) The terminal device performing network access by using
the non-contention based random access is originally in an RRC _CONNECTED state; (2)
When switching, a C-RNTI used by the terminal device in a target cell is configured
by using an identifier (UE-Identity) of a new terminal device of mobility control
information (MobilityControlInfo) in RRC connection configuration.
[0121] The following describes a non-contention based random access method provided in this
application by using specific embodiments.
[0122] FIG. 5 is a signaling interworking diagram of a random access method according to
another embodiment of this application. Referring to FIG. 5, the random access method
includes the following steps. S501. A terminal device receives indication information
sent by a network device.
[0123] The indication information is used to trigger the terminal device to perform random
access. The indication information includes at least one first identifier. The at
least one first identifier is used to instruct the terminal device to determine a
random access time-frequency resource. For example, the first identifier may be a
time index (time index), and the time index is indicated by using a physical broadcast
channel of an SS-block.
[0124] Optionally, the indication information is carried by using physical layer signaling.
The physical layer signaling is, for example, a PDCCH order.
[0125] This step is optional.
[0126] Further, the first identifier is further used to identify an SS-block and/or a CSI-RS.
Specifically, the first identifier is used to identify the CSI-RS, and it may be understood
that the first identifier is used to identify configuration of the CSI-RS. The configuration
of the CSI-RS includes a time-frequency resource of the CSI-RS. Alternatively, the
configuration of the CSI-RS may further include at least one of the following: a sequence,
a port, and the like of the CSI-RS.
[0127] S502. The terminal device sends a preamble to the network device on a random access
time-frequency resource associated with the first identifier.
[0128] S503. The network device determines a sending parameter of a random access response.
[0129] The sending parameter of the random access response is the same as a sending parameter
of the CSI-RS on at least one random access time-frequency resource. The random access
response corresponds to the preamble received by the network device. The sending parameter
of the random access response may specifically be one or more of an angle of departure,
an angle of direction, power angular spectrum of the angle of departure, a transmit/receive
channel correlation, transmit/receive beamforming, a spatial channel correlation,
and the like.
[0130] S504. The terminal device receives the random access response sent by the network
device based on a second identifier.
[0131] Optionally, the indication information may further include the second identifier.
The second identifier is used to instruct the terminal device to determine a receiving
parameter used to receive the random access response, and the second identifier may
specifically be a configuration identifier of the CSI-RS. The configuration of the
CSI-RS includes the time-frequency resource of the CSI-RS. The receiving parameter
of the random access response may be a receiving beam, an antenna parameter, and the
like that are associated with the CSI-RS.
[0132] S505. The terminal device determines success of random access based on the random
access response.
[0133] In this embodiment, the terminal device determines the random access time-frequency
resource based on the first identifier included in the indication information, and
sends the preamble to the network device on the random access time-frequency resource;
correspondingly, after receiving the preamble, the network device\ determines the
sending parameter of the random access response; further, the terminal device determines
the receiving parameter of the random access response based on the second identifier
included in the indication information, and receives the random access response sent
by the network device by using the receiving parameter, so that the terminal device
determines the success of random access in a multi-TRP scenario. For example, the
indication information is sent by using a TRP 2, to instruct the terminal device to
send the preamble to a TRP 1; and then the terminal device receives the random access
response from the TRP 1.
[0134] The following describes an application of the random access method provided in the
embodiment shown in FIG. 5 by using FIG. 6 as an example.
[0135] As shown in FIG. 6, one cell under one base station includes two TRPs: a TRP 1 and
a TRP 2. A terminal device and the TRP 2 are performing data transmission. Primary
synchronization signals and/or secondary synchronization signals included in SS-blocks
sent by the TRP 1 and the TRP 2 are the same. The terminal device receives indication
information sent by the base station by using the TRP 2 in a form of a beam. The indication
information is used to trigger the terminal device to perform random access, to obtain
uplink timing advance of a terminal-TRP 1. The indication information may be carried
in a PDCCH order. Further, the indication information is further used to instruct
the terminal device to perform random access on a random access time-frequency resource
(namely a candidate beam) corresponding to an SS-block 3. The TRP 1 includes a plurality
of SS-blocks, including an SS-block 1, an SS-block 2, the SS-block 3, an SS-block
4, and an SS-block 5. Still further, the indication information may further include
a receiving parameter that corresponds to the CSI-RS and that is used to receive the
random access response.
[0136] FIG. 7 is a schematic structural diagram of a random access device according to an
embodiment of this application. As shown in FIG. 7, the random access device 70 includes:
a determining module 71 and a receiving module 72.
[0137] The determining module 71 is configured to determine a receiving parameter of first
data.
[0138] The receiving module 72 is configured to receive a contention resolution message
by using the receiving parameter.
[0139] The determining module 71 is further configured to determine success of contention
resolution of random access or success of random access based on the contention resolution
message.
[0140] The first data is at least one of the following data: an SS-block, a PBCH, a CSI-RS,
downlink control information of a random access response, a random access response,
and the like.
[0141] Optionally, the receiving parameter may include at least one of the following parameters:
an angle of arrival, a dominant angle of arrival, an average angle of arrival, power
angular spectrum of the angle of arrival, an angle of direction, power angular spectrum
of an angle of departure, a transmit/receive channel correlation, transmit/receive
beamforming, a spatial channel correlation, and the like.
[0142] Optionally, the contention resolution message may be a downlink control channel carrying
an identifier of a terminal device.
[0143] Optionally, the receiving module 72 may further be configured to: before receiving
the contention resolution message by using the receiving parameter, receive configuration
information sent by a network device. The configuration information includes at least
one piece of random access configuration, and a correlation between the first data
and the random access configuration. The random access configuration may include a
random access time-frequency resource, a preamble index, and/or the like.
[0144] In an implementation, the random access device 70 may further include: a sending
module 73, configured to, before the receiving module 72 receives the contention resolution
message by using the receiving parameter, send a preamble to the network device based
on the random access configuration on the random access time-frequency resource. There
is a correspondence between the preamble and the preamble index.
[0145] Further, the receiving module 72 may further be configured to: before receiving the
contention resolution message by using the receiving parameter, receive a random access
response sent by the network device. A receiving parameter of the random access response
is the same as the receiving parameter of the first data, and/or a receiving parameter
of downlink control information of the random access response is the same as the receiving
parameter of the first data.
[0146] The apparatus described in this embodiment may be configured to perform the technical
solutions that are in the foregoing method embodiments and that are executed by the
terminal device or a chip inside the terminal device. The implementation principles
and technical effects are similar, and for functions of each module, refer to corresponding
descriptions in the method embodiments. Details are not described herein again.
[0147] FIG. 8 is a schematic structural diagram of a random access device according to another
embodiment of this application. As shown in FIG. 8, a random access device 80 includes
a receiving module 81, a determining module 82, and a sending module 83.
[0148] The receiving module 81 is configured to receive a preamble sent by a terminal device
on a random access time-frequency resource.
[0149] The determining module 82 is configured to determine a sending parameter of first
data based on the random access time-frequency resource and/or the preamble.
[0150] The sending module 83 is configured to send a contention resolution message to the
terminal device by using the sending parameter, where the contention resolution message
is used to instruct the terminal device to determine success of contention resolution
of random access or success of random access.
[0151] The first data may be at least one of the following data: an SS-block, a PBCH, a
CSI-RS, downlink control information of a random access response, a random access
response, and the like.
[0152] Optionally, the determining module 82 may specifically be configured to: determine
random access configuration based on the preamble and/or the random access time-frequency
resource, where there is a correspondence between the preamble and a preamble index;
and determine the sending parameter of the first data based on the random access configuration
and a correlation between the first data and the random access configuration.
[0153] Optionally, the sending parameter may include at least one of the following parameters:
an angle of departure, an angle of direction, power angular spectrum of the angle
of departure, a transmit/receive channel correlation, transmit/receive beamforming,
a spatial channel correlation, and the like.
[0154] Optionally, the contention resolution message may be a downlink control channel carrying
an identifier of the terminal device.
[0155] Based on the foregoing description, the sending module 83 may further be configured
to: before sending the contention resolution message to the terminal device by using
the sending parameter, send configuration information to the terminal device. The
configuration information includes at least one piece of random access configuration,
and a correlation between the first data and the random access configuration. The
random access configuration may include the random access time-frequency resource,
the preamble index, and/or the like.
[0156] Further, the sending module 83 may further be configured to: before sending the contention
resolution message to the terminal device by using the sending parameter, send a random
access response to the terminal device. A sending parameter of the random access response
is the same as the sending parameter of the first data, and/or a sending parameter
of the downlink control information of the random access response is the same as the
sending parameter of the first data.
[0157] The apparatus described in this embodiment may be configured to perform the technical
solutions that are in the foregoing method embodiments and that are executed by the
network device or a chip inside the network device. The implementation principles
and technical effects are similar, and for functions of each module, refer to corresponding
descriptions in the method embodiments. Details are not described herein again.
[0158] With reference to FIG. 9, the following describes a random access device provided
in an embodiment of this application from a perspective of a network device and a
terminal device.
[0159] As shown in FIG. 9, the terminal device 90 provided in this embodiment of this application
includes at least a processor 91 and a transceiver 92.
[0160] The terminal device may further include a memory 93, storing a computer execution
instruction.
[0161] The processor 91 is configured to determine a receiving parameter of first data and
send an indication to the transceiver 92; the transceiver 92 is configured to receive
a contention resolution message by using the receiving parameter based on the indication
of the processor; and the processor 91 is further configured to determine success
of contention resolution of random access or success of random access based on the
contention resolution message. The first data is at least one of the following data:
an SS-block, a PBCH, a CSI-RS, downlink control information of a random access response,
a random access response, and the like.
[0162] The processor 91 may be configured to perform actions that are implemented inside
the terminal device and that are described in the foregoing method embodiments, and
the transceiver 92 may be configured to perform the transmission to the network device,
sending, or receiving actions performed by the terminal device described in the foregoing
method embodiments. For details, refer to the description in the foregoing method
embodiments, and details are not described herein again.
[0163] In addition, it should be noted that the contention resolution message may be a downlink
control channel carrying an identifier of the terminal device, or the contention resolution
message carries some or all information of a message 3 sent by the terminal device,
to specify a terminal device succeeding in contention of the random access, and the
downlink control channel is used to transmit downlink assignment and/or uplink grant.
If the contention resolution message is the downlink assignment, the transceiver 92
receives downlink data based on the downlink assignment and sends a feedback of the
downlink data to the network device, where the feedback is used to inform the network
device whether the downlink data is successfully decoded by the terminal device 90;
if the contention resolution message is uplink grant, the transceiver 92 sends uplink
data to the network device based on the uplink grant; and if the contention resolution
message is some or all information of the message 3 sent by the terminal device, the
transceiver 92 sends a feedback of the contention resolution message to the network
device, where the feedback is used to inform the network device that the contention
resolution message is successfully decoded by the terminal device, and if the decoding
is not successful, the transceiver 92 does not need to send the feedback to the network
device.
[0164] The processor 91 and the memory 93 may be integrated into a processing apparatus,
and the processor 91 is configured to execute program code stored in the memory 93,
to implement the foregoing functions. In specific implementation, the memory 93 may
also be integrated in the processor 91.
[0165] The terminal device may further include a power supply 94, configured to provide
power to various components or circuits in the terminal device; and the terminal device
may include an antenna 95, configured to send uplink data or uplink control signaling
output by the transceiver 92 by using a wireless signal.
[0166] In addition, to make functions of the terminal device more comprehensive, the terminal
device may further include one or more of an input unit 96, a display unit 97, an
audio frequency circuit 98, a camera 99, a sensor 100, and the like, where the audio
frequency circuit 98 may further include a speaker 981, a microphone 982, and the
like.
[0167] As shown in FIG. 10, a network device 20 provided in this embodiment of this application
includes at least a processor 21 and a transceiver 22.
[0168] In specific implementation, the network device may further include a memory 23, configured
to store a computer execution instruction;
a transceiver 22, configured to receive a preamble sent by a terminal device on a
random access time-frequency resource;
a processor 21, configured to determine a sending parameter of first data based on
the random access time-frequency resource and/or the preamble and send an indication
to the transceiver; where
the transceiver 22 is further configured to send a contention resolution message to
the terminal device by using the sending parameter based on the indication of the
processor 21, where the contention resolution message is used to instruct the terminal
device to determine success of contention resolution of random access or success of
random access.
[0169] The first data is at least one of the following data: an SS-block, a PBCH, a CSI-RS,
downlink control information of a random access response, a random access response,
and the like.
[0170] The processor 21 may be configured to perform actions that are implemented inside
the network device and that are described in the foregoing method embodiments, and
the transceiver 22 may be configured to perform the transmission to the terminal device,
sending, or receiving actions performed by the network device described in the foregoing
method embodiments. For details, refer to the description in the foregoing method
embodiments, and details are not described herein again.
[0171] The processor 21 and the memory 23 may be integrated into a processing apparatus,
and the processor 21 is configured to execute program code stored in the memory 23,
to implement the foregoing functions. In specific implementation, the memory 23 may
also be integrated in the processor 21.
[0172] The network device may further include an antenna 24, configured to send downlink
data or signaling output by the transceiver 22 by using a wireless signal.
[0173] It should be noted that, the processor of the terminal device and the processor of
the network device may be a central processing unit (central processing unit, CPU),
a network processor (network processor, NP), or a combination of the CPU and the NP.
The processor may further include a hardware chip. The hardware chip may be an application-specific
integrated circuit (application-specific integrated circuit, ASIC), a programmable
logic device (programmable logic device, PLD), or a combination thereof. The PLD may
be a complex programmable logic device (complex programmable logic device, CPLD),
a field-programmable gate array (field-programmable gate array, FPGA), a generic array
logic (generic array logic, GAL), or any combination thereof.
[0174] The memory of the terminal device and the memory of the network device may include
a volatile memory (volatile memory), for example, a random access memory (random access
memory, RAM), or may alternatively include a non-volatile memory (non-volatile memory),
for example, a flash memory (flash memory), a hard disk drive (hard disk drive, HDD),
or a solid-state drive (solid-state drive, SSD). The memory may further include a
combination of the foregoing types of memories.
[0175] In the embodiments of this application, the terminal device can communicate with
the network device through unlicensed transmission in a wireless manner. In addition,
the terminal device may alternatively communicate with the network device through
licensed spectrum resource transmission in a wireless manner.
[0176] The network device in the apparatus embodiments of this application may correspond
to the network device in the method embodiments of this application, and the terminal
device may correspond to the terminal device in the method embodiments of this application.
Moreover, the foregoing and other operations and/or functions of each module of the
network device and the terminal device are dedicated for implementing corresponding
procedures in the foregoing method embodiments. For brevity, descriptions of the method
embodiments of this application can be applicable to the apparatus embodiments, and
details are not described herein again.
[0177] In the apparatus embodiments of this application, the terminal device receives the
contention resolution message by using the receiving parameter of the first data,
and determines success of contention resolution of random access or success of random
access based on the contention resolution message. The first data is at least one
of the following data: an SS-block, a CSI-RS, downlink control information of a random
access response, and a random access response, so that for a multi-TRP scenario, the
terminal device can pertinently distinguish whether the received contention resolution
message is a contention resolution message corresponding to current random access.
On the one hand, the terminal device does not continue performing random access after
receiving the contention resolution message corresponding to the current random access,
that is, in the random access procedure, a random access preamble is not sent to the
network device any more; on the other hand, the terminal device is enabled to continue
performing random access before receiving the contention resolution message corresponding
to the current random access, for example, waiting the contention resolution message
corresponding the current random access or resending the random access preamble to
the network device, to implement success of the contention resolution of the random
access or success of the random access by the terminal device for the multi-TRP scenario.
[0178] This application further provides a terminal device, including a memory, a processor,
and a computer program that is stored on the memory and that can be executed by the
processor. The processor executes the computer program to implement the steps performed
by the terminal device in the foregoing method embodiments.
[0179] This application further provides a network device, including a memory, a processor,
and a computer program that is stored on the memory and can be executed by the processor.
The processor executes the computer program to implement the steps performed by the
network device in the foregoing method embodiments.
[0180] This application further provides a terminal device, including at least one processing
element (or chip) configured to perform the method according to the first aspect.
[0181] This application further provides a network device, including at least one processing
element (or chip) configured to perform the method according to the second aspect.
[0182] This application further provides a computer program. When executed by a processor
of a terminal device, the program is configured to perform the steps performed by
the terminal device in the foregoing method embodiments.
[0183] This application further provides a computer program. When executed by a processor
of a network device, the program is configured to perform the steps performed by the
network device in the foregoing method embodiments.
[0184] This application further provides a computer program product, the computer program
product includes a computer program (namely an execution instruction), and the computer
program is stored in a readable storage medium. At least one processor of a terminal
device or a network device may read the computer program from the readable storage
medium, and the at least one processor implements the computer program, so that the
terminal device or the network device is enabled to perform the random access method
provided in the foregoing various implementations.
[0185] This application further provides a computer readable storage medium. When an instruction
in the computer readable storage medium is executed by a processor of a terminal device,
the terminal device is enabled to perform the steps performed by the terminal device
in any one of the foregoing method embodiments.
[0186] This application further provides a computer readable storage medium. When an instruction
in the computer readable storage medium is executed by a processor of a network device,
the network device is enabled to perform the steps performed by the network device
in any one of the foregoing method embodiments.
[0187] This application further provides a communications system, including the terminal
device shown in FIG. 9 and the network device shown in FIG. 10.
[0188] A person of ordinary skill in the art may be aware that, in combination with the
examples described in the embodiments disclosed in this specification, units and algorithm
steps may be implemented by electronic hardware or a combination of computer software
and the electronic hardware. Whether the functions are performed by hardware or software
depends on particular applications and design constraint conditions of the technical
solutions. A person skilled in the art may use different methods to implement the
described functions for each particular application, but it should not be considered
that the implementation goes beyond the scope of this application.
[0189] It may be clearly understood by a person skilled in the art that, for the purpose
of convenient and brief description, for a detailed working process of the foregoing
system, apparatus, and unit, refer to a corresponding process in the foregoing method
embodiments, and details are not described herein again.
[0190] In the several embodiments provided in this application, it should be understood
that the disclosed systems, apparatuses, and methods may be implemented in other manners.
For example, the described apparatus embodiments are merely examples. For example,
the unit division is merely logical function division and may be other division in
actual implementation. For example, a plurality of units or components may be combined
or integrated into another system, or some features may be ignored or not performed.
In addition, the displayed or discussed mutual couplings or direct couplings or communication
connections may be implemented by using some interfaces. The indirect couplings or
communication connections between the apparatuses or units may be implemented in electrical,
mechanical, or other forms.
[0191] The units described as separate parts may or may not be physically separate, and
parts displayed as units may or may not be physical units, that is, may be located
at one position, or may be distributed on a plurality of network units. Some or all
of the units may be selected based on actual requirements to achieve the objectives
of the solutions of the embodiments.
[0192] In addition, functional units in the embodiments of this application may be integrated
into one processing unit, or each of the units may exist alone physically, or two
or more units are integrated into one unit.
[0193] When the functions are implemented in the form of a software functional unit and
sold or used as an independent product, the functions may be stored in a computer
readable storage medium. Based on such an understanding, the technical solutions of
this application essentially, or the part contributing to the prior art, or some of
the technical solutions may be implemented in a form of a software product. The computer
software product is stored in a storage medium, and includes several instructions
for instructing a computer device (which may be a personal computer, a server, a network
device, or the like) to perform all or some of the steps of the methods described
in the embodiments of this application. The foregoing storage medium includes: any
medium that can store program code, such as a USB flash drive, a removable hard disk,
a read-only memory (Read-Only Memory, ROM), a random access memory (Random Access
Memory, RAM), a magnetic disk, or an optical disc.
[0194] The foregoing descriptions are merely specific implementations of this application,
but are not intended to limit the protection scope of this application. Any variation
or replacement readily figured out by a person skilled in the art within the technical
scope disclosed in this application shall fall within the protection scope of this
application. Therefore, the protection scope of this application shall be subject
to the protection scope of the claims.
1. A random access method, comprising:
determining, by a terminal device, a receiving parameter of first data;
receiving, by the terminal device, a contention resolution message by using the receiving
parameter; and
determining, by the terminal device, success of contention resolution of random access
or success of random access based on the contention resolution message, wherein
the first data is at least one of the following data:
a synchronization signal block SS-block, a physical broadcast channel PBCH, a channel
state information-reference signal CSI-RS, downlink control information of a random
access response, or a random access response.
2. The method according to claim 1, wherein the receiving parameter comprises at least
one of the following parameters:
an angle of arrival AoA, a dominant angle of arrival, an average angle of arrival,
power angular spectrum of the angle of arrival, an angle of direction, power angular
spectrum of an angle of departure, a transmit/receive channel correlation, transmit/receive
beamforming, and a spatial channel correlation.
3. The method according to claim 1 or 2, wherein the contention resolution message is
a downlink control channel carrying an identifier of the terminal device.
4. The method according to any one of claims 1 to 3, wherein before the receiving, by
the terminal device, a contention resolution message by using the receiving parameter,
the method further comprises:
receiving, by the terminal device, configuration information sent by a network device,
wherein the configuration information comprises at least one piece of random access
configuration and a correlation between the first data and the random access configuration,
and the random access configuration comprises a random access time-frequency resource
and/or a preamble index.
5. The method according to claim 4, wherein before the receiving, by the terminal device,
a contention resolution message by using the receiving parameter, the method further
comprises:
sending, by the terminal device, a preamble to the network device based on the random
access configuration on the random access time-frequency resource, wherein there is
a correspondence between the preamble and the preamble index.
6. The method according to any one of claims 1 to 5, wherein before the receiving, by
the terminal device, a contention resolution message by using the receiving parameter,
the method further comprises:
receiving, by the terminal device, the random access response sent by the network
device, wherein a receiving parameter of the random access response is the same as
the receiving parameter of the first data, and/or a receiving parameter of the downlink
control information of the random access response is the same as the receiving parameter
of the first data.
7. A random access method, comprising:
receiving, by a network device, a preamble sent by a terminal device on a random access
time-frequency resource;
determining, by the network device, a sending parameter of first data based on the
random access time-frequency resource and/or the preamble; and
sending, by the network device, a contention resolution message to the terminal device
by using the sending parameter, wherein the contention resolution message is used
to instruct the terminal device to determine success of contention resolution of random
access or success of random access, wherein
the first data is at least one of the following data:
a synchronization signal block SS-block, a physical broadcast channel PBCH, a channel
state information-reference signal CSI-RS, downlink control information of a random
access response, or a random access response.
8. The method according to claim 7, wherein the determining, by the network device, a
sending parameter of first data based on the random access time-frequency resource
and/or the preamble comprises:
determining, by the network device, random access configuration based on the preamble
and/or the random access time-frequency resource, wherein there is a correspondence
between the preamble and a preamble index; and
determining, by the network device, the sending parameter of the first data based
on the random access configuration and a correlation between the first data and the
random access configuration.
9. The method according to claim 7 or 8, wherein the sending parameter comprises at least
one of the following parameters:
an angle of departure, an angle of direction, power angular spectrum of the angle
of departure, a transmit/receive channel correlation, transmit/receive beamforming,
and a spatial channel correlation.
10. The method according to any one of claims 7 to 9, wherein the contention resolution
message is a downlink control channel carrying an identifier of the terminal device.
11. The method according to any one of claims 7 to 10, wherein before the sending, by
the network device, a contention resolution message to the terminal device by using
the sending parameter, the method further comprises:
sending, by the network device, configuration information to the terminal device,
wherein the configuration information comprises at least one piece of random access
configuration and a correlation between the first data and the random access configuration,
and the random access configuration comprises a random access time-frequency resource
and/or a preamble index.
12. The method according to any one of claims 7 to 11, wherein before the sending, by
the network device, a contention resolution message to the terminal device by using
the sending parameter, the method further comprises:
sending, by the network device, the random access response to the terminal device,
wherein a sending parameter of the random access response is the same as the sending
parameter of the first data, and/or a sending parameter of the downlink control information
of the random access response is the same as the sending parameter of the first data.
13. A terminal device, comprising:
a processor, configured to determine a receiving parameter of first data and send
an indication to a transceiver;
a transceiver, configured to receive a contention resolution message based on the
indication of the processor by using the receiving parameter; and
the processor, further configured to determine success of contention resolution of
random access or success of random access based on the contention resolution message,
wherein
the first data is at least one of the following data:
a synchronization signal block SS-block, a physical broadcast channel PBCH, a channel
state information-reference signal CSI-RS, downlink control information of a random
access response, or a random access response.
14. The terminal device according to claim 13, wherein the receiving parameter comprises
at least one of the following parameters:
an angle of arrival AoA, a dominant angle of arrival, an average angle of arrival,
power angular spectrum of the angle of arrival, an angle of direction, power angular
spectrum of an angle of departure, a transmit/receive channel correlation, transmit/receive
beamforming, and a spatial channel correlation.
15. The terminal device according to claim 13 or 14, wherein the contention resolution
message is a downlink control channel carrying an identifier of the terminal device.
16. The terminal device according to any one of claims 13 to 15, wherein the transceiver
is further configured to:
before receiving the contention resolution message by using the receiving parameter,
receive configuration information sent by a network device, wherein the configuration
information comprises at least one piece of random access configuration and a correlation
between the first data and the random access configuration, and the random access
configuration comprises a random access time-frequency resource and/or a preamble
index.
17. The terminal device according to claim 16, wherein the transceiver is further configured
to:
before receiving the contention resolution message by using the receiving parameter,
send a preamble to the network device based on the random access configuration on
the random access time-frequency resource, wherein there is a correspondence between
the preamble and the preamble index.
18. The terminal device according to any one of claims 13 to 17, wherein the transceiver
is further configured to:
before receiving the contention resolution message by using the receiving parameter,
receive the random access response sent by the network device, wherein a receiving
parameter of the random access response is the same as the receiving parameter of
the first data, and/or a receiving parameter of the downlink control information of
the random access response is the same as the receiving parameter of the first data.
19. A network device, comprising:
a transceiver, configured to receive a preamble sent by a terminal device on a random
access time-frequency resource;
a processor, configured to determine a sending parameter of first data based on the
random access time-frequency resource and/or the preamble, and send an indication
to the transceiver; and
the transceiver, further configured to send a contention resolution message to the
terminal device by using the sending parameter based on the indication of the processor,
wherein the contention resolution message is used to instruct the terminal device
to determine success of contention resolution of random access or success of random
access, wherein
the first data is at least one of the following data:
a synchronization signal block SS-block, a physical broadcast channel PBCH, a channel
state information-reference signal CSI-RS, downlink control information of a random
access response, or a random access response.
20. The network device according to claim 19, wherein the processor is specifically configured
to:
determine random access configuration based on the preamble and/or the random access
time-frequency resource, wherein there is a correspondence between the preamble and
a preamble index; and
determine the sending parameter of the first data based on the random access configuration
and a correlation between the first data and the random access configuration.
21. The network device according to claim 19 or 20, wherein the sending parameter comprises
at least one of the following parameters:
an angle of departure, an angle of direction, power angular spectrum of the angle
of departure, a transmit/receive channel correlation, transmit/receive beamforming,
and a spatial channel correlation.
22. The network device according to any one of claims 19 to 21, wherein the contention
resolution message is a downlink control channel carrying an identifier of the terminal
device.
23. The network device according to any one of claims 19 to 22, wherein the transceiver
is further configured to:
before sending the contention resolution message to the terminal device by using the
sending parameter, send configuration information to the terminal device, wherein
the configuration information comprises at least one piece of random access configuration
and a correlation between the first data and the random access configuration, and
the random access configuration comprises the random access time-frequency resource
and/or the preamble index.
24. The network device according to any one of claims 19 to 23, wherein the transceiver
is further configured to:
before sending the contention resolution message to the terminal device by using the
sending parameter, send the random access response to the terminal device, wherein
a sending parameter of the random access response is the same as the sending parameter
of the first data, and/or a sending parameter of the downlink control information
of the random access response is the same as the sending parameter of the first data.
25. A terminal device, comprising a memory, a processor, and a computer program that is
stored on the memory and that can be executed by the processor, wherein
the processor executes the computer program to implement a step of the random access
method according to any one of claims 1 to 6.
26. A network device, comprising a memory, a processor, and a computer program that is
stored on the memory and that can be executed by the processor, wherein
the processor executes the computer program to implement a step of the random access
method according to any one of claims 7 to 12.
27. A communications system, comprising the terminal device according to any one of claims
13 to 18 and the network device according to any one of claims 19 to 24.
28. A terminal device, configured to perform the method according to any one of claims
1 to 6.
29. A computer readable storage medium, comprising an instruction, wherein when the instruction
runs on a computer, the computer is enabled to perform the method according to any
one of claims 1 to 6.
30. A computer program product, comprising computer program code, wherein when the computer
program code runs on a computer, the computer is enabled to perform the method according
to any one of claims 1 to 6.
31. A chip, comprising a memory and a processor, wherein the memory is configured to store
a computer program, and the processor is configured to invoke and run the computer
program from the memory, so that the processor is enabled to perform the method according
to any one of claims 1 to 6.
32. A network device, configured to perform the method according to any one of claims
7 to 11.
33. A computer readable storage medium, comprising an instruction, wherein when the instruction
runs on a computer, the computer is enabled to perform the method according to any
one of claims 7 to 11.
34. A computer program product, comprising computer program code, wherein when the computer
program code runs on a computer, the computer is enabled to perform the method according
to any one of claims 7 to 11.
35. A chip, comprising a memory and a processor, wherein the memory is configured to store
a computer program, and the processor is configured to invoke and run the computer
program from the memory, so that the processor is enabled to perform the method according
to any one of claims 7 to 11.